Sonex SONEX TRIGEAR accident near Fawnskin, California, October 20, 2014
On October 20, 2014 at about 5:45 pm local time, a 2007 Sonex SONEX TRIGEAR, registered N91922, was substantially damaged in an accident during maneuvering (low-alt flying) near Fawnskin, California. It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain airspeed after takeoff, which resulted in an exceedance of the airplane's critical angle of attack and a subsequent aerodynamic stall/spin at low altitude. Contributing to the accident was the airplane's reduced climb performance due to a carbon-fouled engine cylinder, the airplane's lack of wheel pants and fairings, and the high density altitude conditions.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 20, 2014 · about 5:45 pm local time
- Place
- Fawnskin, California · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Sonex SONEX TRIGEAR, built 2007
- Registration
- N91922 · no longer on the register · serial 811
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The sport pilot had purchased the airplane 2 days before the accident and was returning it to his home airport. Witnesses observed the airplane shortly after takeoff over a lake near the departure airport, and noted that the airplane was below the elevation of the surrounding terrain. As the airplane approached a cove, it banked left to almost 90 degrees. The nose dropped to a nearly-vertical attitude, and the airplane descended to ground contact. A postaccident examination of the airframe and flight controls revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Examination of the engine determined that one of the four cylinders was carbon-fouled, which was likely the result of an overly rich fuel/air mixture due to the valve adjustment in that cylinder. Given the condition of the cylinder, the 80-horsepower (hp) engine was most likely producing only about 60 hp before the accident. The airplane was not equipped with wheel pants or fairings, which increased drag and further degraded the airplane's performance. Additionally, the density altitude at the time of the accident was over 8,200 ft. Although the pilot had a history of sleep apnea, he was using continuous positive airway pressure (CPAP) therapy, and it is unlikely that his sleep apnea contributed to the accident. Toxicological testing detected citalopram, a prescription medication used to treat depression and panic disorder. The investigation did not determine a definitive psychiatric diagnosis, but no operational evidence of pilot impairment was identified, and it is unlikely that the pilot's use of this medication contributed to the accident. The combination of high density altitude, airplane configuration, and cylinder fouling resulted in significantly decreased performance. It is likely that the airplane's margin above stall speed was minimal as the pilot attempted to climb the airplane after takeoff, and in his attempt to maneuver away from the rising, mountainous terrain, the pilot exceeded the airplane's critical angle of attack, which resulted in an aerodynamic stall/spin.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of control in flight during maneuvering (low-alt flying) defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Capability exceeded
- cause Personnel issues › Action/decision › Action › Incorrect action performance › Pilot
- Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › High density altitude › Awareness of condition
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
Pilot
- Certificate: sport pilot
- Ratings: single-engine land
- Flight time: 500 hours in all
- Medical certificate: Sport Pilot (waiver time limited special)
- Seat: sngl
- Injury: fatal
The aircraft
- Airframe total time: 98 hours
- Last inspection: condition inspection, July 27, 2014
- Maximum gross weight: 1,100 lb
- Seats: 1
- Landing gear: fixed
- Engine: Volkswagon Aerovee 2180 (piston); 11 hours total
The flight
- Departed from: L35 Big Bear CA at 5:35 pm
- Destination: FFZ Mesa AZ
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 290° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 61°F (16°C), dew point 36°F (2°C)
- Altimeter: 30.18 inHg
- Observation at 5:35 pm from KL35
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N91922 the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.